Disable display item caching

Source/platform/graphics/ContentLayerDelegate.cpp

Index: Source/platform/graphics/ContentLayerDelegate.cpp
diff --git a/Source/platform/graphics/ContentLayerDelegate.cpp b/Source/platform/graphics/ContentLayerDelegate.cpp
index bbca97980ef99feee1111ea3e70456a338b9de4a..14a0daad9117b29362e0e58c5b257402f3bbb1e9 100644
--- a/Source/platform/graphics/ContentLayerDelegate.cpp
+++ b/Source/platform/graphics/ContentLayerDelegate.cpp
@@ -75,6 +75,8 @@ void ContentLayerDelegate::paintContents(
     // be needed since Blink will be in charge of creating the display list
     // during the document lifecylcle.
 
+    m_painter->displayItemList()->beginNewPaints();
+
     // Some layers don't yet produce display lists. To handle such layers, we
     // create a canvas backed by an SkPicture, and manually insert this
     // SkPicture into the WebDisplayItemList when the layer's display list is
@@ -89,7 +91,7 @@ void ContentLayerDelegate::paintContents(
     canvas->restore();
     picture = adoptRef(recorder.endRecording());
 
-    ASSERT(m_painter->displayItemList());
+    m_painter->displayItemList()->endNewPaints();
 
     const PaintList& paintList = m_painter->displayItemList()->paintList();
     for (PaintList::const_iterator it = paintList.begin(); it != paintList.end(); ++it)